System for attaching an acoustic element to an integrated circuit

Abstract

A system for attaching an acoustic element to an integrated circuit includes various ways in which to connect piezoelectric ceramic or micro-machined ultrasonic transducer (MUT) elements to an integrated circuit (IC), thus reducing the number of conductors required to connect the acoustic element to the IC by combining the signals in the IC. In another aspect of the invention, the transducer elements include an electrically conductive acoustic layer comprising a backing layer and/or a de-matching layer that is connected to an IC.

What is claimed is:  
     
       1. An ultrasonic transducer probe, comprising: 
       a probe housing;  
       an ultrasonic sensor located in the probe housing and having a plurality of elements;  
       an integrated circuit located in the probe housing; and  
       a redistribution layer between the ultrasonic sensor and the integrated circuit, the redistribution layer having a first surface including circuitry corresponding to the integrated circuit and a second surface including circuitry corresponding to the plurality of elements of the ultrasonic sensor.  
     
     
       2. The transducer probe of  claim 1 , wherein the ultrasonic sensor comprises a piezoelectric element. 
     
     
       3. The transducer probe of  claim 1 , wherein the ultrasonic sensor comprises a micro-machined ultrasonic transducer (MUT). 
     
     
       4. The transducer probe of  claim 3 , wherein the MUT further includes an electrically conductive via associated with each of a plurality of MUT elements, the electrically conductive via configured to provide an electrical connection between the MUT element and the second surface of the redistribution layer. 
     
     
       5. The transducer probe of  claim 1 , wherein the ultrasonic sensor and the redistribution layer are configured as a one-dimensional array. 
     
     
       6. The transducer probe of  claim 1 , wherein the ultrasonic sensor and the redistribution layer are configured as a two-dimensional array. 
     
     
       7. The transducer probe of  claim 1 , wherein the redistribution layer joins to the ultrasonic sensor using solder bumps. 
     
     
       8. The transducer probe of  claim 1 , wherein the redistribution layer joins to the ultrasonic sensor using gold bumps. 
     
     
       9. The transducer probe of  claim 1 , wherein the redistribution layer joins to the ultrasonic sensor using conductive adhesive polymer bumps. 
     
     
       10. The transducer probe of  claim 1 , wherein the redistribution layer joins to the ultrasonic sensor using adhesive polymer thin-line bonding. 
     
     
       11. The transducer probe of  claim 1 , wherein the ultrasonic probe is a transesophageal (TEE) probe. 
     
     
       12. The transducer probe of  claim 1 , further comprising an adhesive material located between the ultrasonic sensor and the redistribution layer, where the adhesive material is a dematching layer. 
     
     
       13. An ultrasonic transducer probe, comprising: 
       an ultrasonic sensor having a plurality of elements, each element including an electrically conductive acoustic layer;  
       an integrated circuit; and  
       a redistribution layer between the ultrasonic sensor and the integrated circuit, the redistribution layer having a first surface having circuitry corresponding to the integrated circuit and a second surface having circuitry corresponding to the plurality of ultrasonic sensor elements.  
     
     
       14. The transducer probe of  claim 13 , wherein the electrically conductive acoustic layer is a backing layer. 
     
     
       15. The transducer probe of  claim 13 , wherein the electrically conductive acoustic layer is a dematching layer. 
     
     
       16. The transducer probe of  claim 15 , wherein the dematching layer provides low acoustic impedance. 
     
     
       17. The transducer probe of  claim 16 , wherein the dematching layer is constructed using material chosen from the group consisting of epoxy, epoxy-metal mixtures and epoxy-silver. 
     
     
       18. The transducer probe of  claim 15 , wherein the dematching layer provides high acoustic impedance. 
     
     
       19. The transducer probe of  claim 18 , wherein the dematching layer is constructed using tungsten-carbide. 
     
     
       20. The transducer probe of  claim 13 , wherein the ultrasonic sensor comprises a piezoelectric element. 
     
     
       21. The transducer probe of  claim 13 , wherein the ultrasonic sensor comprises a micro-machined ultrasonic transducer (MUT). 
     
     
       22. The transducer probe of  claim 13 , wherein the ultrasonic probe is a transesophageal (TEE) probe. 
     
     
       23. An ultrasonic transducer probe, comprising: 
       a probe housing;  
       an ultrasonic sensor located in the probe housing and having a plurality of elements; and  
       an integrated circuit located in the probe housing, wherein the ultrasonic sensor and the integrated circuit are joined using a thin-line bond.  
     
     
       24. The transducer probe of  claim 23 , wherein the ultrasonic sensor comprises a piezoelectric element. 
     
     
       25. The transducer probe of  claim 23 , wherein the ultrasonic sensor comprises a micro-machined ultrasonic transducer (MUT). 
     
     
       26. The transducer probe of  claim 23 , wherein the ultrasonic probe is a transesophageal (TEE) probe. 
     
     
       27. The transducer probe of  claim 23 , further comprising: 
       a pad associated with the integrated circuit and arranged to correspond with the location of each of the plurality of elements of the ultrasonic sensor;  
       a conductor associated with the pad and with each of the elements of the ultrasonic sensor; and  
       where each conductor is joined to each of the plurality of elements of the ultrasonic sensor using an adhesive polymer thin-line bond.  
     
     
       28. The transducer probe of  claim 27 , further comprising a passivation layer applied over and exposing the conductor, where the passivation layer and the conductor are planarized to level the surface of the integrated circuit. 
     
     
       29. A method for constructing an ultrasonic transducer probe, the method comprising the steps of: 
       providing a probe housing;  
       providing an ultrasonic sensor in the probe housing, the ultrasonic sensor having a plurality of elements;  
       providing an integrated circuit in the probe housing; and  
       providing a redistribution layer between the ultrasonic sensor and the integrated circuit, the redistribution layer having a first surface including circuitry corresponding to the integrated circuit and a second surface including circuitry corresponding to the plurality of elements of the ultrasonic sensor.  
     
     
       30. The method of  claim 29 , wherein the ultrasonic sensor comprises a piezoelectric element. 
     
     
       31. The method of  claim 29 , wherein the ultrasonic sensor comprises a micro-machined ultrasonic transducer (MUT). 
     
     
       32. The method of  claim 29 , further comprising the step of configuring the ultrasonic sensor and the redistribution layer as a one-dimensional array. 
     
     
       33. The method of  claim 29 , further comprising the step of configuring the ultrasonic sensor and the redistribution layer as a two-dimensional array. 
     
     
       34. The method of  claim 29 , further comprising the step of joining the redistribution layer to the ultrasonic sensor using solder bumps. 
     
     
       35. The method of  claim 29 , further comprising the step of joining the redistribution layer to the ultrasonic sensor using gold bumps. 
     
     
       36. The method of  claim 29 , further comprising the step of joining the redistribution layer to the ultrasonic sensor using conductive adhesive polymer bumps. 
     
     
       37. The method of  claim 29 , further comprising the step of joining the redistribution layer to the ultrasonic sensor using adhesive polymer thin-line bonding. 
     
     
       38. The method of  claim 29 , wherein the ultrasonic probe is a transesophageal (TEE) probe. 
     
     
       39. An ultrasonic transducer probe, comprising: 
       a probe housing;  
       an ultrasonic sensor located in the probe housing and having a plurality of transducer elements;  
       an integrated circuit located in the probe housing, the integrated circuit including a plurality of electrical pads, wherein each transducer element is located directly above only one corresponding electrical pad; and  
       a plurality of electrical contacts, wherein each electrical contact electrically connects one transducer element with its corresponding electrical pad.  
     
     
       40. The transducer probe of  claim 39 , wherein each of the electrical contacts joins each of the plurality of transducer elements using solder bumps. 
     
     
       41. The transducer probe of  claim 39 , wherein each of the electrical contacts joins each of the plurality of transducer elements using gold bumps. 
     
     
       42. The transducer probe of  claim 39 , wherein each of the electrical contacts joins each of the plurality of transducer elements using conductive adhesive polymer bumps. 
     
     
       43. An ultrasonic transducer probe, comprising: 
       a probe housing;  
       an ultrasonic sensor located in the probe housing and having a plurality of elements;  
       an integrated circuit located in the probe housing, the integrated circuit including a plurality of electrical pads corresponding to the locations of each of the plurality of elements; and  
       a plurality of electrical contacts corresponding to the electrical pads, the electrical contacts being electrically attached to each of the plurality of transducer elements, wherein each of the electrical contacts joins each of the plurality of transducer elements using at least one of gold bumps and conductive adhesive polymer bumps.  
     
     
       44. An improvement to an ultrasonic transducer probe having an ultrasonic sensor and an integrated circuit, comprising: 
       a redistribution layer between the ultrasonic sensor and the integrated circuit, said redistribution layer having a first surface including circuitry corresponding to the integrated circuit and a second surface including circuitry corresponding to a plurality of elements in the ultrasonic sensor.  
     
     
       45. An improved method for constructing an ultrasonic transducer probe having an ultrasonic sensor and an integrated circuit, the improvement comprising the step of: 
       providing a redistribution layer between the ultrasonic sensor and the integrated circuit, said redistribution layer having a first surface including circuitry corresponding to the integrated circuit and a second surface including circuitry corresponding to a plurality of elements in the ultrasonic sensor.